KR100334114B1 - Method for correcting image of scanner - Google Patents

Abstract

According to the present invention, accurate edge information is obtained by removing abnormal vertical black lines of an edge image caused by a lower level of a specific pixel due to a defect of a contact image sensor (CIS) element when detecting an edge of a document for scanning. Regarding the scanner image correction method,

A feature of the present invention is a scanner having a CIS (Contact Image Sensor) for loading a document to be scanned and selecting a copy of an additional function, the scanner comprising: a first process of moving to a white shading position to perform white shading; A second step of detecting and scanning a bad pixel when white shading is performed in the first step, and storing the detected and scanned bad pixel detection image; A third step of starting a prescan for edge detection after performing the second step and storing the detected edge image; A fourth process of recognizing an abnormal pixel and removing the recognized abnormal pixel when an edge image is stored in the third process; And a fifth process of starting and completing copying of the additional function using information obtained by performing an edge detection operation when the abnormal pixel is removed in the fourth process.

According to the scanner image correction method according to the present invention, there is an advantage that the size and position information of a normal document can be obtained by removing abnormal vertical lines in the edge image generated during the edge detection scan.

Description

Method for correcting image of scanner}

The present invention relates to a method for correcting a scanner image, and more particularly, an edge image generated by lowering a level of a specific pixel due to a defect of a contact image sensor (CIS) element when detecting an edge of an original for scanning. A scanner image correction method for obtaining accurate edge information by removing abnormal vertical black lines.

In general, a multifunction device that accommodates all office automation equipment integrates different unique functions so that users can develop and produce high-performance add-on products to reduce the inconvenience and economic burden of using each office automation equipment. Such multifunction devices are equipped with a communication device such as a fax machine, a scanner, a printer, and the like, which use such devices to scan an original and to send and receive scanned original data, and to store the original or received fax in a host computer. I am working on printing data.

1 is a block diagram illustrating a general multifunction printer, and FIG. 2 is a flowchart for performing a method for edge detection of a document using the multifunction device of FIG. 1.

1 and 2, the general multifunction apparatus stores the central processing unit 10, the operation program of the central processing unit 10, and the general control program for controlling the multifunction apparatus overall according to a set program. Memory 20 for storing data according to the program execution of 10), has a plurality of keys (Key) and transmits the key data according to a predetermined key press to the central processing unit 10 and the display data of the central processing unit 10 Key operation unit 30 to display the operating state of the system on the internal display window 31 by scanning an original, converting the image of the original into binarized information, and transmitting it to the central processing unit 10 or transferring the original. The scanner driver 71 of the host computer 70 scans an image of an original such as True Color, 256 Color, Gray, Half-tone, and Line-art. Convert to data The printer 50, which prints the data of the scanner 40, the memory 20, or the data transmitted to the printer driver 72 of the host computer 70, and the CIS (image cell or light emitting diode (LED) element). 60), in order to scan the document using the flatbed scanner 40 without a side, the document to be scanned is loaded (step S10). When the original is loaded in step S10, copying of additional functions such as position conversion, number of page division, original size conversion, etc. of the original is selected (step S11), and pre-scan is started (step S12). When prescan is started in step S12, the edge image of the original is stored in the memory 20 (step S13), and the prescan is completed (step S14).

When the prescan is completed in step S14, the image of the original is filtered by 3x3 (step S15), and the connectivity of the image is checked (step S16). When the image connectivity of the original is inspected in step S16, the central processing unit 10 calculates the position and size of the original (step S17). The copying of the additional function is started using the obtained information up to step S17 (step S18). When the copying of the additional function is completed (step S19), scanning of the original is finished.

However, the following problem occurs when detecting the edge of a document using such a general MFP.

The flat type scanner uses a CIS element. When the CIS element scanning an original image signal is bad and a pixel at a specific position always has a low output level, abnormal vertical lines are generated in the edge image generated when the edge of the original is detected.

Accordingly, an object of the present invention is to solve such a problem, and an object of the present invention is to perform a scan in advance with an edge detection scan condition on a white pad, that is, where white shading is performed before performing a prescan for edge detection. The present invention provides a scanner image correction method that obtains a normal document size and position information by identifying a position of a bad pixel and removing abnormal vertical lines in an edge image generated during an actual edge detection scan.

1 is a block diagram showing a general multifunction device,

2 is a flowchart for performing a method for edge detection of a document using the multifunction apparatus of FIG. 1;

3 is a block diagram of a flat type scanner of the multifunction apparatus according to the present invention;

4 is a flowchart for performing a scanner image correction method according to the present invention.

<Explanation of symbols for main parts of the drawings>

10: chick 20: memory

30: key operating portion 31; Display window

40: scanner 50: printer

60: CIS 70: host computer

71: scanner driver 72: printer driver

In order to achieve the above object, a feature of the present invention is a scanner having a CIS (Contact Image Sensor) for loading a document to be scanned and selecting a copy of an additional function, which performs a white shading by moving to a white shading position. First process; A second step of detecting and scanning a bad pixel when white shading is performed in the first step, and storing the detected and scanned bad pixel detection image; A third step of starting a prescan for edge detection after performing the second step and storing the detected edge image; A fourth process of recognizing an abnormal pixel and removing the recognized abnormal pixel when an edge image is stored in the third process; And a fifth process of starting and completing copying of the additional function using information obtained by performing an edge detection operation when the abnormal pixel is removed in the fourth process.

Preferably, when the white shading is performed, the white shading position is not fixed and the scan for detecting the bad pixel can be performed at different positions of the white panel.

Preferably, when scanning for detection of a bad pixel, the detected edge image is repeatedly searched to determine a location of the bad pixel.

Preferably, it is for removing the black line image by the bad pixel which was located.

Preferably, the black line image is removed to correct an error of edge detection.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are denoted by the same reference numerals as much as possible even if displayed on the other drawings.

3 is a block diagram of a flat type scanner of the multifunction apparatus according to the present invention, and FIG. 4 is a flowchart for performing a scanner image correction method according to the present invention.

In Figures 3 and 4, first describing the flat scanner structure of Figure 3, the CIS 60 can forward or reverse the scan area SA, where a is the CIS 60. ) Is the maximum length that can be moved, b is the maximum length that the CIS 60 can scan, and c represents the white shading position and the detection position of the abnormal pixel. In addition, CHP refers to the home position of the CIS 60, and WSP is a white shading pad.

In FIG. 4, when an original is placed on the scan area SA of the flatbed scanner 40, the original to be scanned is loaded (step S100), and the position of the original, the number of pages divided, the size of the original, etc. The additional function copy is selected (step S101). If copying the additional function is selected in step S101, the document is moved to the white shading position of c on the WSP (step S102), and white shading is performed (step S103). In step S102, the CIS 60, which is at CHP, which is the home position of the flatbed scanner 40, moves to WSP, which is a white shading position for white shading, before obtaining an edge search, and then obtains a profile for white shading. At this time, there is a white pad WSP directly above the CIS 60.

If white shading is performed in step S103, a bad pixel is detected and scanned (step S104), and the detected and scanned bad pixel detection image is stored in the memory 20 (step S105). At this time, by repeating steps S106 and S107 after moving the CIS 60 by a certain distance, it is possible to prevent obtaining wrong information by foreign matter on the WSP, which is a white shading panel, and in step S104, an edge at the WSP, which is a white shading position, is obtained. Scan one line image under the same conditions as prescan for detection.

After performing step S105, prescan for edge detection of black / white binary scan for the entire SA, which is the scan area, is started (step S106), and the detected edge image is stored in the memory 20 ( Step S107).

When the edge image is stored in step S107, the memory 20 is searched to determine the position of the abnormal pixel to recognize the abnormal pixel (step S108), and the abnormal pixel recognized in step S108 is removed (step S109).

In operation S107, the abnormal vertical black lines stored in the memory 20 are removed in operation S109. The black / white binary image stored in the memory 20 has a white level “ Search for bits other than 0 ”.

At this time, when a bit having a blank level of “1” other than a white level of “0” is continuously above a certain size, it is regarded as an abnormal vertical black line image due to an abnormal element of the CIS 60, and the position The abnormal pixel position is stored in the memory 20 for storing. The memory 20 consists of an array of 80 bytes, which is the same as a one line memory on an 80x900 byte map on the memory 20. Each byte described above has a value of “1” when it is normally white, and has a value of “0” when it is abnormal, and only information of pixels whose result values match among the results of multiple scans is valid information. .

In operation S109, data of the vertical black line on the memory 20 is removed by bit completion of 80 bytes of abnormal pixel information of the memory 20 in 900 lines of the memory 20. That is, replace the blank image with a white image.

Meanwhile, when the abnormal pixel is removed in step S109, the edge detection operation is performed by searching the memory 20 from which the abnormal vertical black lines have been removed (step S110), and copying of the additional function using the information obtained in step S110 is started ( Step S111). When the copying of the additional function is started and completed in step S111 (step S112), scanning ends.

As described above, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined by the claims below and equivalents thereof.

As a result, according to the scanner image correction method according to the present invention the following advantages occur.

That is, normal original size and position information can be obtained by removing abnormal vertical lines in the edge image generated during the edge detection scan.

Claims (5)

In a scanner having a CIS (Contact Image Sensor) for loading a document to be scanned and selecting copying of an additional function, Moving to a white shading position to perform white shading; A second step of detecting and scanning a bad pixel when white shading is performed in the first step, and storing the detected and scanned bad pixel detection image; A third step of starting a prescan for edge detection after performing the second step and storing the detected edge image; A fourth process of recognizing an abnormal pixel and removing the recognized abnormal pixel when an edge image is stored in the third process; And And a fifth process of starting and completing copying of the additional function using information obtained by performing an edge detection operation when the abnormal pixel is removed in the fourth process. The method of claim 1, When performing white shading, the white shading position is not fixed, and the scanner image correcting method is characterized in that scanning for detection of bad pixels is possible even at different positions of the white panel. The method of claim 1, The scanner image correcting method, characterized in that the position of the bad pixel is identified by repetitively searching the detected edge image when scanning to detect the bad pixel. The method of claim 1, Scanner image correction method, characterized in that for removing the black line image due to the position of the bad pixels identified. The method of claim 1, Scanner image correction method, characterized in that for correcting the error of edge detection by removing the black line image.